Self-Contained Wireless Camera Device, Wireless Camera System and Method

ABSTRACT

A self-contained wireless camera and a wireless camera system having such a device and a base station. Video processing (e.g. video compression) circuitry of the camera device receives video signals from a camera and provides processed video signals. These are transmitted over a shared radio channel. A radio receiver receives processed (e.g. compressed) video signals from the base station or another camera device. Images from the camera or the base station are displayed in a selected manner on a display or monitor. The base station device receives processed (e.g. compressed) video signals, stores them and retransmits them. A command signal is received by the radio receiver to modify operation in such a manner as to control bandwidth usage. Wireless camera devices can adjust their operation to accommodate other wireless camera devices. Different transport protocol modules can be selected according to the application that the user selects for operation.

This is a divisional patent application of U.S. patent application Ser.No. 11/977,687 filed Oct. 25, 2007, which is a divisional of U.S. patentapplication Ser. No. 09/102,457 filed Jun. 22, 1998, issued as U.S. Pat.No. 6,522,352.

FIELD OF THE INVENTION

This invention relates to wireless camera devices, including but notlimited to video camera devices and still image devices, and it relatesto a wireless camera system comprising a self-contained wireless cameradevice in combination with a base station device. It also relates to anarchitecture for provision of peripheral devices in such a system.

BACKGROUND OF THE INVENTION

Simple master-slave portable wireless video recording devices have beenproposed in the past, designed to produce video and associated signalsand transmit these wirelessly to a recording station. U.S. Pat. No.4,097,893 describes one such analog device, in which start and stop(i.e. pause) operation of the recording station is controlled from thecamera station. Communication of images from the camera station to therecording station is over a VHF or UHF radio channel.

The establishment by the Federal Communications Commission of anonrestrictive usage frequency band in the 5 GHz range, with channelbandwidth capability for high throughput multimedia data transmissioncreates a new opportunity for wireless consumer devices having broaderbandwidth capability than has heretofore been possible. The ability toefficiently use these frequencies requires greater attention to be givento bandwidth management.

Functionality of previously proposed wireless camera devices has beenfairly limited and such devices have so far found little or noacceptance in the consumer marketplace. There is believed to be a demandfor a compact, highly functional, broadband wireless camera device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a simple point-to-point multimedia devicenetwork in accordance with the invention.

FIG. 2 is a block diagram illustrating the elements of a wireless cameradevice according to the preferred embodiment of the invention, withoptional additional elements for purposes of description of a wirelessgateway.

FIG. 3 illustrates a comparison between the protocol structure of adevice according to the preferred embodiment of the invention and astandard protocol structure.

FIG. 4 illustrates a wireless camera system according to a preferredembodiment of the invention.

FIG. 5 is a time diagram illustrating video frame transmission for thepurposes of explanation of re-transmission.

FIG. 6 is a system similar to that of FIG. 4 but with additionalwireless camera devices.

FIG. 7 illustrates a system similar to that of FIG. 6, in the context ofa security system.

FIG. 8 is a table illustrating examples of selection of differentcombinations of parameters for the purposes of bandwidth control.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to FIG. 1, a basic configuration of a system 25 according to apreferred embodiment of the present invention is shown, comprising acamera device 10 and a base station 20, which is illustrated in a basicform as being a radio base station with a monitor, but can be a merestorage and replay device without a monitor or can be a gateway device.

A first stage in defining the potential for a high qualityvideo/audio-based product, such as that of FIG. 1, lies in creation of abasic set of enabling technologies. These technologies are predicated onthe concept that a dedicated set of data transfer and control protocolscan enhance the overall performance and cost profiles of any end productschemes utilizing the approach. The following proposed hardwarearchitecture and communications protocol is intended to provide this lowcost/high performance solution. The dedicated purpose wireless protocollayering model described provides operating advantages via a tightlycoupled integration of communication protocols, which are targeted toprovide an optimum solution to the very specific application oftransferring optimized blocks of audio/video information in a highfrequency digital state. The architecture is consequently less costlybased on this narrower set of protocol requirements and the tighterintegration of the layers. Because the communication protocol processingis highly integrated, it reduces the general protocol service accessrequirements needed in more generally applied interchangeable protocolmodules. It has a focused set of requirements and can thus beimplemented at a very high level of integration, such as a single chipApplication Specific Integrated Circuit (ASIC), which reduces the costof many components while providing the speed needed for some of thehigher data rates.

An architecture for a wireless device is illustrated in FIG. 2. Thedevice comprises a full duplex RF transceiver 100 connected to aprocessor 110, which in turn is connected to a manual input 120 (such asa keypad or control panel), a camera 130 (which has still image andvideo capability but more generally is any image capture device), avideo monitor 140, a speaker 150, and a microphone 160. The transceiver100 comprises a receiver 101 and a transmitter 102.

A network gateway 170, with protocol translator 175, is also shown inphantom outline. This network gateway is optional in a self-containedwireless camera device and is illustrated here for purposes of laterexplanation and description of a base station.

The processor 110 can be a microprocessor or digital signal processor orcan take the form of an ASIC (with or without an integratedmicroprocessor). The exact implementation is not important. Theprocessor 110 comprises a video encoding/decoding module 200 (havingvideo compression circuitry 201 and decompression circuitry 202) coupledat an input and an output of the processor to the camera 130 and thevideo monitor 140 respectively; a still image encoding/decoding module210 (having video compression circuitry 211 and decompression circuitry212) also coupled at an input and an output of the processor to thecamera 130 and the video monitor 140. It also comprises audioencoding/decoding module 220 coupled at an input of the processor 110 tothe microphone 160 and at an output of the processor to the speaker 150.

Within the processor 110 there is also a communications controller 190coupled to the RF transceiver 100. Coupled between the videoencoding/decoding module 200 and the communications controller 190 are areal time video transport protocol module 230 and a verified videotransport protocol module 240. Coupled between the still imageencoding/decoding module 210 and the communications controller 190 are astill image transport protocol module 250. Coupled between the audioencoding/decoding module 220 and the communications controller 190 is anaudio transport protocol module 260. Selection logic 290 is provided,coupled by control connections (shown in dotted outline) to the variousmodules 200-260. The selection logic 290 is coupled to thecommunications controller 190 and to a control data-generating module280, which is coupled to the manual input 120.

In the preferred embodiment, still image encoding/decoding module 210performs discrete cosine transform or block oriented image compression,such as JPEG (Joint Photographers Expert Group) compression and videoencoding/decoding module 200 performs full frame compression, such aswavelet or MPEG (Motion Picture Expert Group) compression. Other typesof compression can be used in the modules.

In operation, images are captured by the camera 130 and encoded ineither video encoding/decoding module 200 or still imageencoding/decoding module 210. They are passed to the respectivetransport protocol module 230, 240 or 250 and passed to thecommunications controller 190 for transmission by the RF transceiver 100over a wideband radio channel. At the same time they can be displayed onvideo monitor 140. Images are received by the RF transceiver 100 andpassed by the communications controller 190 to a selected one of theprotocol modules 230, 240 and 260 and from there to the correspondingvideo encoding/decoding module 200 or still image encoding/decodingmodule 210 for decoding and for display on the video monitor 140.

Audio signals are received by the microphone 160, encoded inencoding/decoding module 220 and passed to the communications controller190 via audio transport protocol module 260, for transmission (withaccompanying video signals if selected). Audio signals are received bythe transceiver 100 (e.g. with accompanying video signals) and arepassed by audio transport protocol module 260 to audio encoding/decodingmodule 220, where they are decoded and output from the speaker 150.

Different transport protocol modules such as modules 230 and 240 areselected according to the application that the user selects foroperation. Thus, real time video transport protocol module 230 isselected for real time video and minimizes delay of transmission anddelay variation to avoid “jitter”, while verified video transportprotocol module 240 performs error correction or selected retransmissionto provide error-reduced transmission at the expense of delay intransmission. The selection of the transport modules 230-260 and theencoding/decoding modules 200-220 is performed by selection logic 290.

There are two principal processes by which selection logic selects thedesired transport modules and the encoding/decoding modules. The firstmethod is by manual selection via the manual input 120 and the secondmethod is by receipt of commands from the RF transceiver 100.

To manually select a transport module and correspondingencoding/decoding module, the user selects an application using themanual input 120. For example, the user can select real time video mode,or verified video mode, or sill image mode and control data generatingmodule 280 generates corresponding control data for selection logic 290to select the corresponding transport protocol module 230,240 or 250 andits corresponding encoding/decoding module 200 or 210.

To remotely select a transport module and correspondingencoding/decoding module, control data is received via radio transceiver100 and passed to selection logic 290 via communications controller 190.As before, the selection Logic selects the corresponding transportprotocol module 230, 240 or 250 and its corresponding encoding/decodingmodule 200 or 210.

Under control of the manual input 120, control data generating module280 can generate control data for transmission via the communicationscontroller 190 through the RF transceiver 100 to another camera deviceor to a base station over the wideband radio channel. If sent to anothercamera device, the control data is received by corresponding selectionlogic in the remote camera device. When control data generating module280 generates control data for transmission to a remote camera device,it can simultaneously cause a selection-by-selection logic 290 ofcorresponding encoding/decoding and transmission modules in the device100.

Control signals or commands that can be generated by control datagenerating module 280 fall into three categories: video controlcommands, video quality control commands and bandwidth control commands.Video control commands include pause, replay, rewind and fast-forward.They also include sets of commands that cause selection of automaticmode vs. manual mode. Video quality control commands include frame size,frame resolution, frame rate, compression type and compression ratio.Bandwidth control commands define percentage of allocation of bandwidthfor a given camera or from one camera to another, expressed as abandwidth allocation value or a proportion of available bandwidth for asthe number of camera devices permitted in a band.

Video encoding/decoding module 200 and real time video transportprotocol module 230 can together be viewed as first video processing andvideo reconstruction circuitry that provide to the transceiver 100selectively processed first video signals processed according to aselected protocol scheme and provide reconstructed second video signalsto the monitor 140. Similarly, video encoding/decoding module 200 andverified video transport protocol module 240 can together be viewed assecond video processing and video reconstruction circuitry that provideto the transceiver 100 selectively processed first video signalsprocessed according to a different selected protocol scheme and providereconstructed second video signals to the monitor 140. Similarly,reliable still image encoding/decoding module 210 and reliable stillimage transport protocol module 250 can together be viewed as thirdvideo processing and video reconstruction circuitry.

Each selected protocol scheme has at least one of a selectable transportprotocol, a selectable image coding (compression/decompression)protocol, a selectable audio protocol scheme and a selectable controlprotocol. Selection of different protocols gives rise to differentbandwidth usages and allows more optimized or balanced usage ofavailable bandwidth.

The architecture described and illustrated integrates the variouscommunication protocol layers into a common processing block between thephysical layer and the application layer. This architecture decouplesthe communication protocol layers from the RF transceiver functionalblock. It also decouples the communication protocol layers from themultimedia I/O which represents the application layer. The architectureis based upon a presumed system in which a variety of transmission andreception devices are operating.

Encoding/decoding algorithms and transport protocols are configured andoptimized based on the multimedia data type and the user's preferences.These various data paths converge upon the more common networking,bandwidth allocation, and RF medium access protocols.

FIG. 2 shows that there are differences in transport protocol for realtime video and verified video. Real time video, and real time audio areisochronous. This means that these transport protocols must balance thereliable transfer concerns with the timing required for properpresentation at the receiving end. For verified video or audio, theintended immediate destination for the multimedia data is not real timepresentation, but rather storage. It is referred to as “verified” sincehigher levels of reliable transfer (e.g. higher error correction and/orretransmission) can be used without high bandwidth usage.

The protocol layer stack model to be used in the proposed architectureis compared to the International Telecommunication Union (ITU) standardnetwork protocol layer model in FIG. 3.

On the left hand side of the figure, the standard ITU protocol layermodel is illustrated, comprising a physical layer 300 and a data layerlink layer 301 having a link level reliability sub-layer 302 and a mediaaccess control sub-layer 303. Above the data link layer is a networklayer 304 and above the network layer 304 are a session layer 306, apresentation layer 307 and an application layer 308. To the right ofthis standard model is illustrated, for purposes of comparison, theprotocol layer stack model for a camera device according to thepreferred embodiment of the invention. This model comprises an RF modem350, a layer 361 which integrates encoding/decoding, encryption,transport protocol, network protocol, bandwidth allocation, and mediaaccess control. The encoding/decoding and encryption is an applicationspecific presentation layer. The transport protocol is an applicationspecific reliability protocol. Above these integrated protocol layers isthe application 362.

The RF modem layer 350 is implemented in the full duplex RF transceiver100 of FIG. 2. The integrated protocol layers 361 are implemented in theprocessor 110 of FIG. 2 and the application layer 362 is implemented inthe form of the camera 130, the video monitor 140, the speaker 150, themicrophone 160, and the network gateways 170 of FIG. 2. In the preferredembodiment, the integrated protocol layers 361 are admitted on a logicboard and a radio control board, in which processes of the protocolbelow the dotted line of FIG. 3 are implemented on the radio controlboard and processes above the dotted line are implemented on a logicboard. In effect, this has the result that the encoding/decoding modules200, 210 and 220 and the transport protocol modules 230, 240,250 and 260are all implemented on the logic board and the communications controller190 is implemented on a separate communications control board. Theselection logic 290 and the control data-generating module 280 areimplemented on the logic board. These details are, of course, notcritical and greater integration can be achieved with all the elementsof the integrated critical layers being implemented in a single, highlyintegrated module.

The advantages of a proprietary multimedia communications protocol stackover the ITU standard for this architecture is optimum use of bandwidth,cost, performance, and the flexibility to tailor the protocols for thevarious multimedia transmissions.

The ITU standard seeks to define each layer independently and to definea set of protocol access points between each layer. The strictinterpretation of this model results in creating a set ofinterchangeable protocol building blocks that provide a very generalsolution to digital communications networking. Each general purposeprotocol building block tends to be a costly, yet reasonable solutionfor a broad range of networking challenges. This architecture iscritical for heterogeneous, standardized networks that are built fromcommercially available, interoperable components. Conversely, thededicated purpose architecture now described builds a homogeneous RFwireless network with a uniquely qualified set of components.

The architecture described focuses upon providing optimum solutions fora particular family of wireless devices. It provides transmissionreliability at the link layer and not on an end-to-end regime. (Anend-to-end reliability is not needed since there is no multiple-hoprouting in the common uses of the wireless network.) If an applicationis developed which needed end-to-end reliability within the wirelessnetwork, layers can be added between the application layer 362 and theintegrated protocol processing block 361. For the current applications,the transmission reliability is specific tailored to the needs of theuser, the multi-media data type being transferred, and the RFenvironment.

The architecture described operates in a somewhat closed homogeneous RFwireless network. The limited set of components that operate within thenetwork only need to be interoperable with each other. The closed natureof the network allows value added features to be included, with acontrolled, limited impact upon existing device interoperability. Theability to include such value added features, allows the wirelessproduct developer to differentiate this product from the others in themarket using other network approaches. The closed aspect of thisarchitecture does not, however, limit interoperability with other, moregeneral purpose networks. Network gateways 170 bridge the wirelessnetwork with other standard networks. FIG. 4 illustrates the use of agateway to interconnect the proposed wireless network to standardnetworks.

The presence or absence of network gateways 170 in a particular devicedepends on the function of that device. For example, a self containedwireless video or still camera need not have network gateways 170, whilea dedicated base station preferably has network gateways 170 but doesnot have the camera 130, video monitor 140, speaker 150 or microphone160. Accordingly, the particular application layer devices that areincluded in any particular product will depend on the intended functionof the camera device product.

Referring to FIG. 4, the wireless camera device of FIG. 1 is showncommunicating over a wideband radio channel 400 to a wireless multimediagateway 401 and a wireless disk drive 402 and a wireless monitor 403, aswell as other miscellaneous devices which will not be described indetail, but may include a lap-top computer 404, a remote control device405 and a printer 406. Each of the devices 100 and 401 thru 406 has anarchitecture as described with reference to FIG. 2 and FIG. 3. Thegateway 401 communicates with a multi-media personal computer 410 havinga monitor 411 and audio speakers 412 and it communicates with a publicor private network 420.

The wireless multimedia gateway depicted in FIG. 4 provides protocoltranslation to convert the wireless protocol to the standard publicnetwork protocol or the standard PC interface protocol. The gatewayconverts the focused, optimized protocol used on the wireless network togeneral purpose protocol, such as Internet protocol (IP) used in theopen system networks. In essence the gateway provides the wirelessnetwork devices with points of interoperability to outside systems. Theprovision of the gateway 401 has a number of advantages, including theability to network multiple camera devices and operate them under remotecontrol.

This invention, in its preferred embodiment, also provides flexibilityof bandwidth usage for video quality and transmission reliabilitytradeoffs. Bandwidth can be traded for video quality and transmissionreliability based on the needs of a given application. The approachdescribed is inherently bandwidth sensitive. The estimated peakbandwidth limit is at least 10 Mbps. This rate is sufficient to supportvarious combinations and quality levels of the transmission of video,still images, audio, data, graphics and text. A goal is to provide abandwidth usage strategy that will accommodate the maximum number ofdevices in a wireless network with highest possible transmissionreliability and the level of video quality necessary for a givenapplication.

Video quality and reliability are singled out for discussion over othermultimedia types because of the large demand placed on bandwidth byvideo transmission and the bandwidth tradeoffs that are possible withvideo. Video quality is represented as resolution of each video frame,the rate at which the video frames are updated and compression rate ofthe transmitted video.

The resolution of still images that make up the video are only limitedby the image sensor of the camera. Given a high end image sensor, videoresolution can be supported in a range from HDTV (high definitiontelevision) or high resolution computer monitor quality to very smallthumbnail images. The lower the video resolution the more grainy thevideo image appears. Higher video resolution will require commensuratehigher bandwidth usage for transmission. Selection of video resolutionis based on the application demands and/or the user's preferences.

Video frame rate is the speed that still image frames are presented uponthe monitor of the base station 20 or the monitor 140 of the cameradevice to produce the illusion of full motion video. The describedtechnology can support video frame rates ranging from NationalTelevision Standards Committee's (NTSC) standard of 60 interlaced fieldsper second through stop action video used for video conferencing tosingle frame still images. Slower than the above noted video frame ratescan introduce an unintended effect of jerkiness in the motion of highspeed “action” video sequences. Faster video frame rate signals willrequire higher bandwidth usage for transmission. Selection of videoframe rate is, again, based on the application demands and/or the user'spreferences.

Video compression rate is an indication of the amount by which the videodata has been reduced using various compression techniques. Forinstance, broadcast quality, uncompressed digital video requires abandwidth of 150 Megabits per second (Mops). Given 10 Mbps limit of theRF subsystem, uncompressed digital video transmission is not practical.Current standard video compression algorithms, including MPEG, wavelet,or H.320, will compress video to within these speed limitations. Anyvideo compression will cause some loss of the video data, but the amountof loss can be limited based on the video compression rate. Lower ratesof video compression provide higher perceived image quality and use morebandwidth. The compression ratio/bandwidth tradeoff is dependent uponthe application. A baby monitor, for instance, could operate with a highvideo compression rate and use less bandwidth because of the lowerdemands for image quality.

As with video quality, the unique timing requirements of video directlyrelate to reliability. As discussed earlier, there is a different set ofconcerns with the transmission of real time video versus verified video.As previously noted, real time video is a video stream that is playedback, to the user's perception, immediately upon reception. Verifiedvideo, or non-real time video, is not intended to be played backimmediately, but rather is stored for later viewing.

The transmission of real-time video must be isochronous to preventbuffer over flow or underflow in the receiving end. In other words asteady flow of video data must be received such that it can be displayedwithout either running out of or being overrun by video data. Non-realtime video is not sensitive to this problem, unless the transmitting endis in danger of overrunning its buffers between the image acquisitionand transmission phases.

The transmission of real time video and non-real time video presents atradeoff in reliability. The reliable transmission of video data thatresults in later video delivery for a real time application serves nopurpose. Specifically, video that is not received within thepresentation time will cause a frame skip. In the event that a frame isto be presented but has not been completely received, a buffer underflowcondition occurs which results in a frame skip. Transmission of non-realtime video is not constrained by the timing of immediate playback. As aresult more reliable transmission methods can be used to create anon-real time yet verified video transmission, thus the term “verifiedvideo”.

Re-transmission can be used to provide some limited measure ofreliability for real time video transmission. A goal of this method isto provide time for transmission retries prior to presentation time. Themethod tends to balance the amount of reliability and allocation, withbandwidth or larger receive buffer sizes and increased video latency.FIG. 5 presents a simplified example of video frame transmission timingwhich illustrates some of the parameters for the retransmission method.In practice the technique may be complicated by such issues as the MPEGvideo compression scheme, which does not always transmit full videoframes.

As FIG. 5 shows, a burst of video frame data at bandwidths higher thanthe constant video rate will provide time for transmission retries priorto the next video frame burst. Beginning at time t the image capturedevice (e.g. camera 130) has captured a complete video frame N. Startingat this time it is the function of the transport protocol layer todeliver this frame reliably to the corresponding transport protocollayer at the receiving end.

Time t+1 (which occurs following a guard band following precedingactivity on the channel), the transmitter transmits the video frame N ina data burst, completed at the time t+2. Starting at time t+2, there isa period extending to time t+3 during which the transport protocol layermodule of the receiving device (specifically verified video transportprotocol module 240 of FIG. 2) receives the video frame N data burst,performs error correction using any embedded error correction code inthe data burst and determines whether the data burst is receivedcorrectly. If it is not received correctly, the verified video transportprotocol module of the receiver sends a negative acknowledgment messageto the verified video transport protocol layer module of the transmitterand there is an opportunity for the transmitter to perform a re-try,retransmitting video frame N data burst. At time t+4 illustrated by thedotted line in FIG. 5, there is a deadline for receiving video frame N.If the receiver does not successfully receive video frame N before thisdeadline, the video frame is dropped.

The receiver has a timer (not shown in FIG. 2) which commences timing attime t+2 (or can commence timing at t+1), as measured at the receivingend, and if the receiver transport layer protocol cannot determinebefore time t+4 that frame N has successfully been received, it dropsthe frame and awaits the next video frame data burst N+1. This databurst is transmitted by the transmitting device at time t+5, ending attime t+6. The receiver (assuming it has successfully received videoframe N data burst) waits until time t+7 before presenting video frame Non the receiver monitor. By delaying until time t+7, the receiver hasthe time from t+4 until t+7 as its minimum received video processingtime. If the receiver fails to receive video frame N data burst, it cansimply present the preceding video frame. The overall latency in thesystem is from time t to time t+7. Every frame will be delayed by thereceiver until time t+7 (regardless of whether the frame was receivedbefore time t+4), with the result that jitter at the receiver monitor isavoided.

Using this technique, average video bandwidth increases based on theaverage number of retries. The video burst rate of bandwidth that isneeded to support this method depends upon the amount of time left forretries, which in turn dictates the reliability of the transmission.

Time for transmission retries can also be increased by providing morebuffer space for in transit video data. Increased buffering willincrease the video latency which, as shown in the FIG. 5, is the timebetween capturing and presenting the video. The amount of acceptablevideo latency will be dependent upon the application. For example, longvideo latencies in a two-way interactive video application can beawkward and distracting to the users.

Real time audio is also isochronous and as such shares these sameissues. However, due to lower bandwidth requirements for audio, thisissue is not as costly to solve in terms of bandwidth, processing power,and end-to-end latency.

In case of audio/video program transmissions, the audio and videopresentations are synchronized.

The method of access control to the RF media is not critical. Methodsthat can be employed include Frequency Division Multiplex (FDM)techniques or Time Division Multiplex (TDM) techniques or in someadvanced cases Code Division Multiplex (CDM) techniques. Methods mayalso include fixed allocation of bandwidth or dynamic allocation ofbandwidth based on need.

It is not critical whether a decentralized type of media access controlis used in, or a direct central control of allocation by a gateway isused. For instance, decentralized control has the advantage of allowingany combination of wireless devices to interact, without the addedexpense of a central control unit. A decentralized control approach alsominimizes the risk of single point failure.

The wireless transmission technology in the lightly regulatedenvironment of the 5.2 GHz band is very flexible. The flexibility ofthis technology can be taken advantage of to develop a whole family ofproducts, each with its own characteristic use of the technology. Thoseproducts share many common attributes. For example, if they are tointeroperate at the local area level, each must: support a subset of thevarious multimedia transport protocols; provide the RF and antennacontrol sections; and share a networking and RF media access controlalgorithm.

One of the primary issues of a network protocol in a wireless network isto allocate bandwidth and time slots to the members of the network. Thisissue favors a tight integration of network and media access controllayer. For the purpose of explanation of bandwidth allocation andcontrol, FIG. 6 is presented, illustrating a network such as that ofFIG. 4 with the addition of second and third wireless camera devices 600and 601.

In the complex network, of FIG. 6, a “smart” control of bandwidth basedon the user's intentions is provided.

Under this scenario, the user may have multiple low resolution videoinputs. In the event that the user wishes to focus in detail on theoutput of a single video source, e.g. wireless camera device 600,commands to increase frame rate or resolution may be sent to the cameradevice 600 (or other input device). At the same time, commands are sentto the other video image capture devices 100 and 601 to reduce theirframe rates or resolution in an effort to balance the bandwidth usage.

The capability described enables the organization of a number of “local”RF clusters of devices into logically accessible “higher level” groupsthat shield the user from the specific internal system details of thatorganization, and still permit an authorized remote user to modify theoperation of any particular device.

One simple application example that could use this approach would be acampus security system illustrated in FIG. 7 that has a considerablenumber of wireless devices providing audio and visual surveillance.These devices could be arranged in groups 700 and 701 at variousphysical locations, (for instance at doors and windows of the buildingsin the complex). These “local” RF clusters of devices could beinterconnected by standardized Local Area Networks (LAN's) 710 toprovide access to the devices from display equipment located anywhere onthe LAN (e.g. security monitoring stations 715 and 720 via wirelessgateways 716 and 721).

This approach to organizing the access to the devices provides a verypowerful logical mapping or switching capability. For instance, themedia information from a group of cameras located on the rear of thefirst building could be accessed as a single file of media data thatcontains multiple time stamped views and is logically labeled as“Building One—Rear Loading Dock”. In addition, the users operating thedisplay equipment could change various operating parameters of thesurveillance equipment for maximum flexibility.

FIG. 8 illustrates examples of various parameters that can be adjustedto control bandwidth utilization between multiple devices operating on acommon bandwidth. The various rows in the table of FIG. 8 are differentparameters that can be adjusted or selected and the different columnsshow various examples of how these parameters give rise to differentbandwidth utilization estimates.

The adjustable parameters fall into four broad categories: imageparameters, audio parameters, control parameters and transportparameters. Selectable image parameters include frame size, frameresolution, frame rate, compression type, compression rate, compressionratio and auto mode. Selectable audio parameters include number of audiochannels, sampling rate, compression type, compression ratio and automode. Control parameters include local operation, remote operation andon-demand mode. Transport parameters include real time (i.e. no errorcorrection) verified (i.e. with error correction), variable and automode.

In examples 1 and 2 of FIG. 8 the frame size is 512×512 and the frameresolution is 270×352. In the first example the frame rate is 15 framesper second, the compression type is JPEG, the compression ratio is 50%and auto mode is off. In the second example, the frame rate is 30 framesper second, the compression type is wavelet #1, the compression ratio is30% and the auto mode is off. For examples 1 and 2 the audio parametersare the same and the control parameters are the same. In example 1 errorcorrection is used while in example 2 error correction is not used. As aresult of these alternative selections of parameters, example 2 givesrise to higher bandwidth utilization than example 1. In the table theestimated bandwidth utilization of example 2 is 50%, while the estimatedbandwidth utilization for example 1 is only 30%.

From this, it can readily be seen that two cameras can simultaneously beoperated using the high frame rate and high level of verification ofexample 2, but if a third camera device is to enter the same bandwidth,it would be preferable (indeed necessary) for all three cameras torevert to the combination of parameters illustrated in example 1. Theswitching from the set of parameters of example 2 to the set ofparameters of example 1 takes place in response to each camera that isoperating according to the parameters of example 2 receiving a controlcommand requiring those cameras to degrade to a lower bandwidthutilization. The control command can come from a central controller suchas the security monitoring station 715 of FIG. 7 or can come from thethird camera (e.g. camera device 601 of FIG. 6) making a request toenter the shared bandwidth. The latter scenario provides an ad hocnetwork in which all users would voluntarily degrade as the networkbecame more congested. In such an arrangement it is preferable toprovide a minimum level of service (e.g. that of example 1) beyond whicha given device would not degrade further. Upon reaching this minimumlevel of service, all devices being requested to degrade respond with anegative acknowledgment, in effect telling the requesting device that nofurther bandwidth is available.

The third example of FIG. 8 has the same frame size as the first twoexamples, but has a higher frame resolution of 480×352 pixels and usesMPEG compression. Two audio channels are provided, using MPEG audiocompression, and remote and on demand control is enabled. In thisexample, a single wireless camera device will use 75% of the availablebandwidth. Clearly when a single camera device operates using theseparameters, no other device is able to enter the channel (unless thatother device can enter at a bandwidth utilization even lower than thebandwidth utilization of example 1).

In the scenario of FIG. 7, in the event that a user monitoring thesurveillance area from one of the security monitoring stations 715 and721 wishes to examine with greater scrutiny a particular camera, acommand can be sent to one of the cameras (e.g. camera device 601 ofFIG. 6) instructing that camera to increase its resolution as shown inexample 3 of FIG. 8 and to change its compression type, while at thesame time frames are sent to other camera devices (e.g. devices 10 and600) instructing those camera devices to degrade completely, either byceasing transmission or by reducing their frame rates to a very lowlevel.

In the preferred embodiment, selection logic 290 of FIG. 2 comprises apre-programmed table of different levels of service in which differentcombinations of parameters of FIG. 8 are preprogrammed. In this manner,a user can select, through manual input 120, a particular package ofparameters to support a particular desired application. Examples ofpackages of desired parameters could include still images, scenic video,motion video, security surveillance, etc. According to the selectedapplication, the optimum package of parameters is selected.

Referring one again to FIG. 6, the provision of gateway 401 makes thehome wireless network a conduit for audio/video recording and playback,video on demand from an outside network, and wireless network browsing(as well as other functions) simultaneously. In a multi-user,multi-function environment, shared components such as monitors or diskdrives 402 must be addressable and may also must provide a form ofdedicated access to prevent users from corrupting each other's data.

The system is easy for the consumer to use and reconfigure. The initialproducts should be capable of detecting the components in the systemconfiguration and acting accordingly. Adding a new component to thesystem should not pose a technical challenge to the user.

Privacy and security algorithms are included that allow a home'swireless components to interact without concern that components outsidethe home network can gain access or provide interference. Thesealgorithms provide authentication and encryption. As new components thatare added to the network, each is easily synchronized with the uniquesecurity “keying” that provides secure access.

Some of the main product configurations for video and/or audio deliveryare: point to point video; multi-point video; full duplex video; andpoint-to-point, multi-point, full duplex audio.

The point to point video category encompasses the set of applicationswhere there is a need to transmit video from an origination site to areception site. Multi-point video encompasses the set of applicationswhere there is a need to transmit video to or from an origination siteto multiple reception sites. Full duplex video includes the set ofapplications where there is a need to transmit and/or receive video fromtwo or more origination and/or reception sites.

The same options exist for audio configurations to be added to most ofthe video configurations.

The range of these potential configurations are illustrated by FIG. 6.Many of the potential product embodiments described based upon the coretechnology require connection with outside, standard networks such asthe Internet. In this case, a device class for providing datatranslation support also present an opportunity for provision ofdedicated purpose, integrated application modules. Termed “wirelessgateway” for this discussion, this class of devices share some commoncharacteristics.

Various models and options of wireless gateways may be provided. Allwireless gateway models capability of receiving and transmitting atbandwidth levels that are necessary to transfer the various multimediadata types, remote control, or transport protocol signaling. Wirelessgateways must be capable of supporting the features of the other devicesin the premise's wireless network, as well as the user's externalconnection requirements. Each user will have a different set ofexpectations for connection to the outside world and potential hardwirednetworks within the household that the gateway may support.

A high end model wireless gateway could provide expansion slots forvarious Network Interface Cards (NIC). The fully equipped gateway maysupport cable modems, satellite antenna connections, and telephonelines, to the external world as well as internal hardwired networks suchas Ethernet.

The wireless multimedia gateway contains the capability of highbandwidth receive and transmit. For instance, it can receive verifiedvideo and still images for storage. It may transmit video either realtime to the monitor or verified video and still images for transfer tothe PC or the network, or it may transmit and receive at much lowerrates for remote control and transport protocol signaling.

The gateway may also provide direct access to non-wireless sharedresources, such as disk drives and printers. The gateway provides theability to receive remote control from either a directly connected PC,an incoming telephone call, or a wireless remote control device. Remotecontrol commands from a PC or the external network may be routed toother hardwired wireless devices.

Various models of wireless video image acquisition devices such ascameras may be provided. All camera models can use high bandwidth fortransmission of real time video data and each can use low bandwidth totransmit and receive for remote control and transport protocolsignaling. Higher end camera models may provide more flexibility andcapabilities in terms of video frame rates, image resolution and videocompression rates. They may also support synchronized audio and video.Inexpensive camera applications, such as an infant monitor, can havelower target bandwidth usage by taking advantage of low resolution imagesensor, fixed transmitted resolutions, slow, fixed rate video framing,and high video compression ratios.

The wireless monitor supported by this modular system could also imposea wide range of demands. In one embodiment, it could be a high bandwidthreceive device and low bandwidth transmit device. It may receive realtime audio/video only for immediate playback or still images fordisplay. It, in turn, may transmit and receive at much lower rates forremote control and transport protocol signaling. Other various models ofwireless video monitors may also be provided, each with its own minimumand maximum demands. For instance, some monitor models may use highbandwidth for reception of video stream data or high resolution stillimages. Higher end monitor models will likely provide more capabilitiesin terms resolution and compatibility with the higher end cameras.

Monitor 403 is able to receive real time video whether it is receivedfrom a camera or a storage device. Added options may include provisionof a port for a photo printer that prints the currently displayed stillimage or video frame. Among the advanced features of a wireless monitorthere may be an option to split the screen for inputs from varioussources or display on screen information in the form of overlays ordigital effects. This option is also highly dependent upon how thebandwidth is shared between various components.

The storage peripheral 402 denoted as “wireless disk drive,” has thecapability of high bandwidth data receive and transmit. It receivesverified audio/video and still images for storage. It is also capable ofreceiving real time audio/video for applications that both record andplay back simultaneously. An optional feature is transmission ofaudio/video data in either real time mode to the monitor or verifiedaudio/video and still images for storage to the gateway. As with othernetwork devices, the drive transmits and receives at much lower ratesfor remote control and transport protocol signaling. This deviceprovides storage that can be archived and is easily expandable. (Oneconfiguration option may support a removable hard disk type device toprovide such capability. For instance, one and two gigabyte removabledisks are available on the market today that provide sufficient storagefor log video streams and a multitude of still images. Even a 100Megabyte removable disk would be useful for fairly extended videostreams.)

More than one type of wireless video disk drive may be provided. Allwireless disk chive models bear the capability of both receive andtransmit using variable bandwidths needed to transfer the variousmultimedia data types, remote control, or transport protocol signaling.The higher end wireless disk drive models provide more capabilities interms of storage and multiple user support features.

In summary, the system described optimizes the relatively unregulatedcharacteristics of the new frequency allocation to provide extremelyhigh quality transmission in a small, low cost and power efficient endproduct package, enabling the creation of a revolutionary class ofvideo-enabled, personal communication devices.

The various arrangements described above and illustrated in the figuresare given by way of example only and modifications of detail can be madeby one of ordinary skill in the art without departing from the spirit anscope of the invention.

1. A wireless camera device comprising: a camera; video compressioncircuitry coupled to the camera, the video compression circuitryreceiving signals from the camera and providing compressed video signalscompressed according to a compression scheme; still image compressioncircuitry coupled to the camera, the still image compression circuitryreceiving signals from the camera and providing compressed still imagesignals compressed according to a compression scheme; and a radiotransmitter coupled to the video compression circuitry and to the stillimage compression circuitry for transmission of the compressed video andstill image signals.
 2. The wireless camera device according to claim 1,further including a user selection input coupled to the videocompression circuitry and to the still image compression circuitry, thesignals from the camera being compressed according to a selected one ofat least two compression schemes, dependent on the user selection input.3. The wireless camera device according to claim 2, wherein the at leasttwo compression schemes comprise a still image compression scheme and avideo compression scheme.
 4. The wireless camera device according toclaim 3, further wherein the still image compression scheme comprisesJPEG.
 5. The wireless camera device according to claim 3, furtherwherein the video compression scheme comprises MPEG.
 6. The wirelesscamera device according to claim 1, further including a radio receiverfor receipt of a compressed signal from a base station.
 7. The wirelesscamera device according to claim 6, further wherein the compressedsignal is a video signal.
 8. The wireless camera device according toclaim 6, further wherein the compressed signal is a still image signal.9. The wireless camera device according to claim 6, further includingdecompression circuitry coupled to the radio receiver, the decompressioncircuitry receiving the compressed signal from the base station andproviding a decompressed signal.
 10. The wireless camera deviceaccording to claim 9, further including a display selectively coupled tothe camera and the video decompression circuitry, the displayselectively displaying an image from the camera and an image representedby the decompressed signals.
 11. A method of operation of a wirelesscamera device comprising: receiving a signal from a camera, the signalselected from the group consisting of video signals and still imagesignals; if the received signal is a video signal, providing videosignals compressed according to a video compression scheme; if thereceived signal is a still image signal, providing still image signalscompressed according to a still image compression scheme; andtransmitting the compressed signal.
 12. The method of claim 11, furtherincluding a user selecting if the signal is a video signal or a stillimage signal, and compressing the signal from the camera according to aselected one of at least two compression schemes, dependent on the userselection.
 13. The method of claim 12, further including if the userselects a video signal, a video compression scheme.
 14. The method ofclaim 13, further including if the user selects a video signal, an MPEGcompression scheme.
 15. The method of claim 12, further including if theuser selects a still image signal, a still image compression scheme. 16.The method of claim 15, further including if the user selects a stillimage signal, a JPEG compression scheme.
 17. The method of claim 11,further including the camera device receiving a compressed video signal.18. The method of claim 17, further including the camera devicereceiving a compressed video signal and providing a decompressed videosignal.
 19. The method of claim 18, further including the camera deviceselectively displaying an image from the camera and an image representedby the decompressed video signal.